Integrated circuit card

ABSTRACT

The invention relates to an integrated circuit card ( 1 ) comprising: an input/output block ( 4 ) for receiving external command data from an interface device ( 2 ); a central processing unit (CPU) ( 3 ) in signal communication with the input/output block ( 4 ) for performing a task corresponding to the received command data; a judgement block ( 5 ) in signal communication with the central processing unit ( 3 ) for judging whether a working time of the central processing unit ( 3 ) reaches a reference time, after an input of the external command data is completed; and a control block ( 6 ) in signal communication with the judgement block ( 5 ) for operating responsive to an output of the judgement block, wherein the control block controls such that a S(WTX request) is output via the input/output block ( 4 ) without intervention by the central processing unit whenever the interface device ( 2 ) connected to the integrated circuit card ( 1 ) transmits a command to the integrated circuit card and the integrated circuit card is not able to respond to this command within the defined maximum waiting time.

FIELD OF THE INVENTION

The invention relates to an integrated circuit card according to thefeatures of claim 1.

BACKGROUND OF THE INVENTION

Integrated circuit (IC) cards are well known and they are very oftenused for identification e.g. to allow an otherwise restricted access toa facility or for allowance of certain financial transactions by theuser of such an integrated circuit card.

An integrated circuit card is a card which contains an integratedcircuit and which receives and transmits data according to an interfacedefined e.g. by ISO Standard 7816. Therefore electronic signals, datastructure and transmission protocols of the integrated circuit are e.g.defined in ISO 7816-3. ISO 7816 is an international standard whichdefines characteristic features of such integrated circuit cards. Forexample ISO 7816-1 defines the physical characteristics of suchintegrated circuit cards and ISO 7816-3 defines the electronic signalsand transmission protocols.

With asynchronous half-duplex character transmission protocol as definedby ISO 7816-3, hereinafter referred to as “T=1 transmission protocol”,if an interface device transmits a command to an integrated circuit cardand the integrated circuit card is not able to respond to this commandwithin the defined maximum waiting time, the integrated circuit card hasto transmit a WTX-request, hereinafter referred to waiting timeextension request, i.e. a S-block requesting a waiting time extension tothe interface device. Usually block frames transmitted by the card maycomprise I-blocks as so called information blocks, R-blocks as so calledreceive ready blocks and S-blocks as so called supervisory blocks.According to the value of certain bit fields within these blocks, theycan be coded as different commands or messages.

In particular, the S-block command S(WTX request) is transmitted fromthe integrated circuit card to the interface device in order to gain anadditional working time when a time needed to process the receivedcommand exceeds the maximum Character-/Block-Waiting-Time.

The interface device resets a timer for measuring aCharacter-Waiting-Time or Block-Waiting-Time when the S(WTX request)block is transmitted from the integrated circuit card, so that thewaiting time is reset.

In the case of the aforementioned T=1 transmission protocol, theintegrated circuit card has to transmit the S(WTX request) block to theinterface device before the time taken to process the input commandexceeds the maximum waiting time. This means that a central processingunit of a conventional integrated circuit card must stop executing thecommand being currently executed in order to process a procedure fortransmitting the S(WTX request) block. As is well known, the integratedcircuit card processes a command according to an application program.For this reason, the procedure for transmitting the

S(WTX request) block causes program overhead. In addition, in caseswhere it is impossible to stop execution of a current input command, theinterface card does not receive a response from the integrated circuitcard within the work waiting time and treats a current communicationstate as a communication error. Accordingly, normal communicationbetween the interface device and the integrated circuit card is notcompleted. This leads to disadvantages and errors in communication of aintegrated circuit card and an interface device.

SUMMARY OF THE INVENTION

Therefore it is an object of the invention to create an integratedcircuit card which mitigates the above mentioned problems.

The above mentioned problems will be solved by using an integratedcircuit card comprising: an input/output block for receiving externalcommand data from an interface device; a central processing unit (CPU)in signal communication with the input/output block for performing atask corresponding to the received command data; a judgement block insignal communication with the central processing unit for judgingwhether a working time of the central processing unit reaches areference time, after an input of the external command data iscompleted; and a control block in signal communication with thejudgement block for operating responsive to an output of the judgementblock, wherein the control block controls such that a S(WTX request) isoutput via the input/output block without intervention by the centralprocessing unit whenever the interface device connected to theintegrated circuit card transmits a command to the integrated circuitcard and the integrated circuit card is not able to respond to thiscommand within the defined maximum waiting time.

Furthermore it is of advantage that the integrated circuit card isworking in the T=1 transmission protocol.

According to the invention the S(WTX request) is a supervisory blockwaiting time request.

Additionally it is of advantage that the code of the S(WTX request) in a6-bit pattern is “000011”.

Furthermore it is more advantageous that the judgement block sets theinput/output block to a reception mode when transmission of theprocedure data has been ended.

Additionally it is of advantage that the judgement block sets thecontrol block to an acknowledge-reception mode when transmission of theprocedure data has been ended.

According to another embodiment of the invention the integrated circuitcard checks the S(WTX response) block sent by the interface device inreturn to the S(WTX request) block previously sent by the integratedcircuit card. Further advantages of the invention are described withreference to the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the invention will beapparent from the following description of an exemplary embodiment ofthe invention with reference to the accompanying drawings, in which:

FIG. 1 shows a schematic view of an integrated circuit card.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic view of an integrated circuit card 1 which isin communication with an interface device 2. The circuit card contains acentral processing unit 3 or handling input data from the interface,outputting data to the interface or treating data according to theinternal processes and methods to calculate or compare data to achieve adesired result. An embodiment of an inventive circuit card 1 is capableof automatically transmitting a waiting time extension request WTXwithout intervention by the central processing unit (CPU). Such waitingtime extension requests are e.g. S(WTX) blocks as defined in the T=1Protocol.

According to one aspect of the present invention, an integrated circuitcard 1 includes an input/output block 4 for receiving external commanddata; a central processing unit 3 for processing the received commanddata; a judgement block 5 for judging whether the processing runtime ofthe central processing unit 3 reaches a reference time, after an inputof the external command data is completed; and a control block 6 foroperating responsive to an output of the judgement block 5, wherein thecontrol block 6 controls such that procedure data (e.g., an S(WTX)block) is output via the input/output block 4 without intervention bythe central processing unit 3 whenever the processing runtime of thecentral processing unit 3 reaches the reference time.

In an advantageous embodiment of the invention, the judgement block 5sets the input/output block 4 to a reception mode when transmission ofthe procedure data has been ended.

In a further advantageous embodiment of the invention, the judgementblock 5 sets the control block 6 to an acknowledge-reception mode whentransmission of the procedure data has been ended. This allows to checkthe S(WTX response) block sent by the interface device 2 in return tothe S(WTX request) block previously sent by the integrated circuit card1. The control block 6 signals the result of the S(WTX response) blockevaluation to the central processing unit 1, if the waiting time requestis not acknowledged by the interface device 2.

According to an other advantageous embodiment, the judgement block 5comprises: an oscillator 7 circuit configured to generate a clocksignal; a register 8 configured to store the reference time; a counter 9configured to count in synchronization with the clock signal when aninput of the command data is completed; and a comparator 10 for judgingwhether a count time of the counter reaches the reference time. Thecounter 9 is reset by an output of the comparator 10 when the input ofthe command data is completed or when the count time of the counterreaches the reference time. The judgement block further comprises aswitch circuit 11 that transfers the clock signal to the counter 9 whenthe input of the command data is completed.

REFERENCES

-   1 integrated circuit card-   2 interface device-   3 central processing unit-   4 input/output block-   5 judgement block-   6 control block-   7 oscillator-   8 register-   9 counter-   10 comparator-   11 switch circuit

1. Integrated circuit card comprising: an input/output block forreceiving external command data from an interface device; a centralprocessing unit (CPU) in signal communication with the input/outputblock for performing a task corresponding to the received command data;a judgement block in signal communication with the central processingunit for judging whether a working time of the central processing unitreaches a reference time, after an input of the external command data iscompleted; and a control block in signal communication with thejudgement block for operating responsive to an output of the judgementblock, wherein the control block controls such that a S(WTX request) isoutput via the input/output block without intervention by the centralprocessing unit whenever the interface device connected to theintegrated circuit card transmits a command to the integrated circuitcard and the integrated circuit card is not able to respond to thiscommand within the defined maximum waiting time.
 2. The integratedcircuit card of claim 1, wherein the integrated circuit card is workingin the T=1 transmission protocol.
 3. The integrated circuit card ofclaim 1, wherein the S-(WTX request) is a supervisory block waiting timerequest.
 4. The integrated circuit card of claim 1, wherein the code ofthe S(WTX request) in a 6-bit pattern is “000011”.
 5. The integratedcircuit card of claim 1, wherein the judgement block sets theinput/output block to a reception mode when transmission of theprocedure data has been ended.
 6. The integrated circuit card of claim1, wherein the judgement block sets the control block to anacknowledge-reception mode when transmission of the procedure data hasbeen ended.
 7. The integrated circuit card of claim 1, wherein theintegrated circuit card checks the S(WTX response) block sent by theinterface device in return to the S(WTX request) block previously sentby the integrated circuit card.